OK, I wanted to replace the 500G disks in a Dell T20 server with new 2TB disks. The machine has 4 SATA ports, one used for the optical disk and three for the hard drives. It is set up with /dev/sda and /dev/sdb with each three partitions: 1 -- VFAT (for EFI) 2 -- ext4 (for /boot) 3 -- LVM /dev/sda2 and /dev/sdb2 are a mirror raid (/dev/md0) /dev/sda3 and /dev/sdb3 are a mirror raid (/dev/md1), with LVM on top of that. /dev/sdc is a disk containing one file system and mostly used by AMANDA for backup (it has a "virtual" tape changer). This morning I shut the machine down and pulled [the 500G] /dev/sdb and installed a new 2TB disk as a new /dev/sdb. Partitioned it (with parted) to be much like /dev/sda (except partition 3 is way bigger). I added the new /dev/sdb2 to /dev/sda2 (boot raid set) and dd'ed /dev/sda1 to /dev/sdb1. I then created a new RAID set (degraded) with /dev/sdb3, used pvcreate on it, used vgextend to add it to the system volume group, then used pvmove to move the extents from the old disk to the new disk. Meanwhile I partitioned a second 2TB disk using a USB SATA dock and copied the old 500G /dev/sdc1 to the new 2TB disk. So far so good. Then I shut the machine down, swapped in the new backup [2TB] disk and pulled the old system [500G] disk and installed the third new [2TB] disk. The system won't boot that way. It seems there is something in the UEFI (secure boot) logic that wants the original disk, even if everything is moved over. I ended up putting the original /dev/sda in. The machine boots and is using the new system disk (a raid array in degraded mode). What is the magic to fix this? I tried to run efibootmgr, but it wants a model named efivars loaded, but there is no such module available. What am I missing? -- Robert Heller -- 978-544-6933 Deepwoods Software -- Custom Software Services http://www.deepsoft.com/ -- Linux Administration Services heller at deepsoft.com -- Webhosting Services